Recently, wireless charging techniques have been developed. One type of wireless charging may use electromagnetic induction, while another type may use magnetic resonance. These charging methods have been increasingly utilized in electronic devices such as smart phones. In such systems when the power transmitting unit (PTU) (e.g., a wireless charging pad) and the power receiving unit (PRU) (e.g., a smart phone) come into contact with each other or are within a certain distance of each other, the battery of the power reception device can be charged via electromagnetic induction or electromagnetic resonance between a transmission coil of the power transmission device and a reception coil of the power reception device.